The story: a good and honest man, expelled from a grand house, subjected to a life of oppression, undertakes an epic journey on horseback with an unlikely companion (one of the duo a valet). Narrowly escaping death, he becomes an expert and ruthless killer, continuing the quest to find the eponymous hero’s beloved, with whom he is finally reunited against all the odds.

Sound like Django Unchained? It also happens to be the plot of another highly controversial work, written around 250 years ago: Voltaire’s Candide. The points of comparison are many, but whether we look at the main themes or the tiny details, the influence of Voltaire’s novella becomes increasingly evident. Agreed, the ‘hero returns’ plot has been done by everyone since Homer, but Tarantino’s violence, his humour and his characterisation are so clearly inspired by Candide it’s a wonder no one has picked him up on it.

Paramount to both works is the subject of slavery. Published in 1759, Voltaire’s Candide was the great scandalising satire of its time, widely banned for blasphemy and sedition. Is Tarantino looking to create the 21st-century version? As he told Channel 4 News: “I’ve always wanted to explore slavery… to give black American males a western hero… [who] would pay back blood for blood. I am responsible for people talking about slavery in America in a way they have not in 30 years.”

Of course, his critics see it differently. “American slavery was not a Sergio Leone spaghetti western,” Spike Leetold VibeTV. “It’s disrespectful to my ancestors to see that film.”

Linked to the subject matter is its treatment through excessive violence. Just as Voltaire satirises brutal military oppression with systematic, exaggerated and quasi-slapstick carnage, Tarantino cheapens the horror of white oppression and heinous violence inflicted on black slaves with a ridiculous, hyperbolic shoot-em-up parody, full of gory, sexed-up and highly unrealistic scenes of slaughter and copious squirts of red blood. (The director is renowned for such over-the-top violence, yet when confronted with the question of whether it could have any effect on real life, he eloquently informed Channel 4’s Krishnan Guru-Murthy in the aforementioned interview: “I’m shutting your butt down.”)

Candide’s picaresque storyline involves a long perambulation of the world, and at one of the high points of Django, with the killing of Monsieur Candie, the camera dwells pointedly on a spinning globe. Both heroes’ journeys lead from the old world to new frontier territories – Django discovering Texas, which only joined the union 30 years previously, while Candide explores South America – but in each case the hero returns to his old world at the end for the denouement. When Australians turn up in the antebellum American South at the end of Django Unchained, the ridiculousness of it all seems strangely Voltairesque.

In terms of characterisation, a single letter separates the names of Tarantino’s villain Calvin Candie and Voltaire’s hero. Monsieur Candie, slave trader par excellence, is an avid Francophile and insists on being called Monsieur (though he can’t speak French), and names his slave after the hero from Dumas’s The Three Musketeers. Is there an ironic nod here on the part of a director who has always been an avid Francophile (though he can’t speak French), and who named his production company after the same nouvelle vague classic that inspired Pulp Fiction’s dance sequence?

Candide’s heroine Cunégonde is obviously German; Django’s lost love Broomhilda (a corruption of the Norse/Germanic Brünnhilde) must be the only black slave to have grown up speaking German in the Deep South. Each has a name with a double entendre, one a pun on genitalia, the other meaning “ready for battle”.

Is it simple coincidence that Django becomes the fastest shot in the South, just as Candide’s speed and precision with his rapier is incomparable? Two seemingly good men don’t flinch when it comes to cold-blooded killing, or donning their victim’s clothes and hats. Tarantino adopts the slightest of gestures of characters from Candide. Dr Shultz’s delight when he hears his native language German after so many years mirrors Cunégonde’s when she speaks to her former servant; his constant sinister twirling of the mustache echoes that of Don Fernando.

In the bigger picture, both of these heroes are free men – but their options are limited as to where they can roam, Django because of the overpowering white supremacy that ruled the southern states, and Candide for fear of being burned or killed by evil armies.

Tarantino is a self-confessed magpie; he draws on everything from 70s blaxploitation films to B westerns and violent Filipino films. But questions remain about one of the key influences on his latest film. Could the ninth-grade dropout have drawn so heavily on Voltaire’s 18th-century masterpiece without knowing it? Have its 18th-century plot devices become so much a part of our cultural lexicon that Django’s accumulation of such an extraordinary number of elements from Candide be just a coincidence? And – conversely – is Voltaire’s text now so obscure that most film critics have never come across it?